Selling something doesn’t seem that hard. You take your item, list a price that works for you and see who is interested. Maybe you adjust the price to fit the market better. Perhaps someone tries to haggle, after all, in some countries that is always expected. Then you see demands that you give it for free. Or a trade offer for a broken, used car that is less than a third of the value of your item. 75$ for a 250$ smartphone.
After her husband went way too far with a 'prank', this wife became concerned that her marriage may never be the same.
If you don't want food poisoning, you might want to skip the potluck altogether...